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CN-121985915-A - Vertebra stabilizing device

CN121985915ACN 121985915 ACN121985915 ACN 121985915ACN-121985915-A

Abstract

The invention relates to a vertebral stabilization device comprising at least two screws having a first section engageable in a vertebra and a threaded second section, the two sections being separated by a flange, at least one first connecting rod for connecting the second section of the screws, and at least a first and a second fixation assembly for fastening the rod to the screws. Each securing assembly comprises at least one clamp and a nut, the clamp being arranged to clamp the first rod. The holder comprises a first jaw and a second jaw, which are identical and held together by a resilient member. According to a variant of the invention, the device may comprise a third fixing assembly having at least one gripper with a first jaw and a third jaw having an inner surface identical to the inner surface of the first jaw and an outer surface complementary to the outer surface of the second jaw.

Inventors

  • PAUL FAYADA
  • Pascal Lockchem

Assignees

  • 保罗·法亚达

Dates

Publication Date
20260505
Application Date
20240925
Priority Date
20231004

Claims (7)

  1. 1. A vertebral stabilization device comprising: -at least two screws (1 a, 1 b), each screw having a first threaded section (1.1 a, 1.1 b) to be engaged in a vertebra (Va, vb) and a second threaded section (1.2 a, 1.2 b) separated from the first threaded section by a flange (2); -at least one first connecting rod (3) having two opposite ends for connecting the second threaded sections of the screw to each other, and -At least one first (F) and second (F') fixing assemblies for attaching the end of the rod (3) to the screw (1 a, 1 b), each fixing assembly comprising at least one clamp (5) engageable on the second threaded section (1.2 a, 1.2 b) of one of the screws (1, 2) and arranged to clamp one end of the first rod (3), and a nut (8) having a lower bearing surface and arranged to be screwed onto the second threaded section (1.2 a, 1.2 b), screwing the clamp (5) against the upper surface of the flange (2 a, 2 b) of the screw (1 a, 1 b), The at least one gripper (5) comprises a first jaw (5 c) and a second jaw (5 d) identical to each other and held together by means of a resilient holder (6), the first jaw comprising an inner surface (5 c.1) facing an inner surface (5 d.1) of the second jaw (5 d), the inner surface comprising, at the level of a first connection portion (5.3) of each jaw, a complementary shaped recess (5.31) and protrusion (5.32), the first connection portions (5 c.3, 5 d.3) engaging each other to form a hinge.
  2. 2. The vertebral stabilization device according to claim 1, characterized in that the first part of each jaw comprises two semi-cylindrical surfaces having the same diameter and the same length, extending continuously to each other in the width direction of the jaw, the first cylindrical surface forming the protrusion (5.32) and the second cylindrical surface forming the recess (5.31).
  3. 3. A vertebral stabilization device according to claim 1 or 2, characterized in that each jaw comprises, opposite to the first portion (5.3), a second portion (5.4) for connection to the rod (3), the second connection portion comprising a concave receiving surface (5.41) arranged to receive a portion of the rod (3) and having a depth smaller than the radius of the rod.
  4. 4. A vertebral stabilization device according to claim 3, characterized in that the concave receiving surface (5.41) of the second part (5.4) has an axis parallel to the hinge axis of the hinge formed by the first part (5.3).
  5. 5. A vertebral stabilization device according to any one of claims 1 to 4, characterized in that, beside the first portion (5.3), each jaw (5 c, 5 d) comprises a third portion (5.5) for connection to the screw (1), which third portion comprises a cylindrical frustoconical through hole (5.51) having a larger diameter adjacent to the outer surface (5 c.2, 5 d.2) of the jaw (5 c, 5 d) opposite to the inner surface (5 c.1, 5 d.1) and a smaller diameter adjacent to the inner surface (5 c.1, 5 d.1).
  6. 6. The vertebral stabilization device according to any of claims 1 to 5, characterized in that the third portion (5 c.5, 5 d.5) of each jaw (5 c, 5 d) comprises a convex outer surface (5 c.2, 5 d.2) in the shape of a spherical cap, which is complementary to the spherical cap shape of the flange (2) or of the upper surface of the nut (8).
  7. 7. The vertebral stabilization device according to any of claims 1 to 6, characterized in that it comprises at least one second connecting rod (3 ') and a third fixation assembly comprising at least one gripper (10) which can be engaged on the second threaded section (1 a ' ', 2, 1' ', b.2) of one of the screws (1 a ' ', 1' b ' ') and is arranged to grip one end of the second rod (3 '), said gripper comprising a first jaw (5 e) and a third jaw (9) having an inner surface (9.1) identical to the inner surface (5 e.1) of the first jaw (5 e) and an outer surface (9.2) in the shape of a concave spherical cap complementary to the outer surface (5 c.2, 5 d.2) of the second jaw (5 c, 5 d).

Description

Vertebra stabilizing device Background The present invention relates to the field of surgical implants, and more particularly to a vertebral stabilization device implanted in a human or animal body for the treatment of spinal disorders. There are many vertebral stabilization devices whose general principle is to connect adjacent vertebrae via a rod. In a first type of device, rods (sometimes also referred to as sticks) are attached to both sides of the vertebrae to be connected along a plane substantially parallel to the median sagittal plane of the spinal column. The device enables the vertebrae to be very well stabilized relative to each other, but significantly limits the mobility of the spine, impeding or even preventing certain movements of the patient. According to this first type of device, the rod is inserted directly into the heads of the pedicle screws, which requires perfect alignment of the screw heads with each other, which is sometimes difficult to achieve. In up>A second type of device described in document WO-up>A-2018/019792, the rods are attached to the vertebrae such that the rods cross on the median sagittal plane of the spinal column. The latter device allows a certain mobility to be maintained between the two vertebrae connected by the device while at the same time enhancing the stability of the two vertebrae. The rod has a first end in the shape of a torus and a second end in the shape of an elliptical torus. During installation, the rings engage respectively on threaded sections of extended pedicle screws that are screwed directly into the vertebrae. Final attachment of the vertebrae is obtained by screwing a nut onto each threaded section to lock the ring of the rod by tightening, thereby tightening the position of the rod with respect to the pedicle screw. This attachment principle, while simple, is difficult to adjust accurately. Furthermore, when the nut is tightened, the rod may be slightly displaced around the attachment element, changing the initial adjustment by the surgeon. It will thus be appreciated that a vertebral stabilization device must allow stabilization/attachment of the vertebrae while seeking to preserve the maximum possible mobility for the patient. These devices must also enable the surgeon to adjust the device as finely as possible. The documents FR-up>A-2 865 377, WO-up>A-98/55038, EP-up>A-1 665 994 therefore disclose devices comprising pedicle screws screwed into vertebrae, the heads of which are shaped in such up>A way that they can receive up>A pin on which up>A clamp of one end of up>A clamping rod engages. Adjustment is made possible by the relative movement of the pin with respect to the screw. The main drawback of these different systems is that they comprise a plurality of components to be assembled, which increases the cost of the device and lengthens the duration of the surgical procedure. Object of the Invention The present invention aims, inter alia, to overcome at least some of the above drawbacks by providing a vertebral stabilization device that is compact, consists of few parts and is easy and quick to implant. Disclosure of Invention To this end, there is provided a vertebral stabilization device comprising: -at least two screws, each screw having a first threaded section to be engaged in a vertebra and a second threaded section separated from the first threaded section by a flange; At least one first connecting rod having two opposite ends for connecting the second threaded sections of the screws to each other, and -At least one first and second fixing assembly for attaching the end of the rod to the screw, each fixing assembly comprising at least one clamp engageable on the second threaded section of one of the screws and arranged to clamp one end of the first rod, and a nut having a lower bearing surface and arranged to be screwed onto the second threaded section, tightening the clamp against the upper surface of the screw flange. According to the invention, in this case the at least one gripper comprises a first jaw and a second jaw which are identical to each other and are held together by means of a resilient holder. The first jaw includes an inner surface facing an inner surface of the second jaw. At the level of the first connection portion of each jaw, the inner surface comprises complementary shaped recesses and protrusions, the first connection portions engaging each other to form a hinge. Thus, the vertebral stabilization device according to the invention comprises only four different components, a screw, a rod, two identical clamping jaws, and a nut. The surgeon will thus be able to stabilize at least two vertebrae using at least one stabilization device according to the present invention. Stabilization of the vertebrae is easily carried out by means of a rod, which is simply attached by means of a clamp of each fixing assembly, said clamp consisting of two identical jaws, the first engagement portions of which form a hinge. Stab